DESCRIPTION: Dr. Sale proposes to define the mechanisms that regulate dynein activity by modulating motor function and controlling where the motor is localized. Two specific aims are proposed: (1) to determine how changes in IC138 phosphorylation regulate the I1 dynein complex; and (2) to determine the mechanism by which I1 is targeted to the inner doublet microtubules, and to test the hypothesis that axonemal kinase and phosphatase are anchored.